Tim Allen is a Hollywood star known for making people laugh in shows like “Home Improvement” and “Last Man Standing.” That’s why it would surprise many fans that Allen has a dark history with drugs and alcohol.

Allen, who has been sober for 23 years, served almost two-and-a-half years in federal prison after he was caught with more than a pound of cocaine at Michigan’s Kalamazoo/Battle Creek International Airport in 1978. He was only 23 at the time.

While appearing on the “WTF with Marc Maron” podcast, Allen opened up about this time in his life, and discussed what prison was like for him.

“I just shut up and did what I was told,” the star said. “It was the first time ever I did what I was told and played the game … I learned literally how to live day by day. And I learned how to shut up. You definitely want to learn how to shut up.”

After about eight months in prison, Allen said he “got used to” being in lockup and even had “OK times.”

Allen went on to say that his struggles began after his father was killed by a drunk driver when he was only 11 years-old.

“After my old man died, I really just played games with people and told adults what they wanted to hear and then stole their booze,” he said.

Allen said that when he looks back at his life, he feels great “shame” over some of the things he did, given how his father died.

“I look back on those things, this is sober guy stuff, I had so much shame at the things that I did … especially driving people around,” he said. “Coming from a dad that was killed that way, it’s difficult to get past it.”

“I love my life. I’m not any more mentally stable, I have the same issues I had,” Allen added. “Now, I can’t hide from them.”

The ninth and final season of Allen’s sitcom “Last Man Standing” is currently airing, and Allen admitted to Fox News that it was “horrible” going to set every day knowing that it was one day closer to the final day of production.

“I thought it would be a good idea,” Allen said. “It was a terrible idea!”